Lift gate apparatus

ABSTRACT

A lift gate apparatus includes a movable conveyor device and a bracket. The movable conveyor device is configured to transition between a conveying position and a non-conveying position. The bracket configured to bridge a gap between the movable conveyor device and a fixed conveyor device, wherein the bracket pivots and slides over the fixed conveyor device when the movable conveyor device is transitioned from the conveying position to the non-conveying position.

RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional ApplicationSer. No. 17/156,983 entitled “LIFT GATE APPARATUS” filed on Jan. 25,2021, which claims the benefit of priority to U.S. ProvisionalApplication Ser. No.: 62/981,776 entitled “LOW PROFILE LIFT GATE WITHRETRACTABLE GAP ROLLERS” filed on Feb. 26, 2020, each of which isincorporated by reference herein in its entirety.

TECHNOLOGICAL FIELD

Example embodiments of the present invention relates generally to aconveyor system for handling items, and, more particularly, to a liftgate apparatus in use with the conveyor system.

BACKGROUND

Material handling systems are traditionally used to convey, sort, andorganize items (e.g., cartons, cases, etc.) at high speeds. Depending onthe configuration of the system, the items may travel through the systemin an unregulated manner or may be consolidated into a single stream ofitems. Conveyor systems may rely on a conveyor controller and/orwarehouse management system to organize items through all stages ofhandling and processing.

Conventional conveyor systems may also include a conveyor bed in theform of conveyor rollers or belts supported on a conveyor frame.Examples of such conveyor systems may include a sorter conveyor system,a merge conveyor system, an accumulation conveyor system, an inductionconveyor system, or the like. These conveyor systems may be distributedat different locations within a warehouse or a distribution center. Fewof these conveyor systems may be located at a confined space within thewarehouse due to space constraints. In this regard, accessibility to theconveyor systems becomes difficult during maintenance due to theconfined space as one of the conveyor systems may block a pathway toaccess another conveyor system making it difficult for an operator or amaterial handling vehicle to access the conveyor systems.

SUMMARY

The following presents a simplified summary to provide a basicunderstanding of some aspects of the disclosed material handling system.This summary is not an extensive overview and is intended to neitheridentify key or critical elements nor delineate the scope of suchelements. Its purpose is to present some concepts of the describedfeatures in a simplified form as a prelude to the more detaileddescription that is presented later.

Various example embodiments described herein relate to a lift gateapparatus includes a movable conveyor device and a bracket. The movableconveyor device is configured to transition between a conveying positionand a non-conveying position. The bracket configured to bridge a gapbetween the movable conveyor device and a fixed conveyor device, whereinthe bracket pivots and slides over the fixed conveyor device when themovable conveyor device is transitioned from the conveying position tothe non-conveying position.

Various example embodiments described herein relate to the lift gateapparatus including a lifting mechanism to lift the movable conveyordevice to the non-conveying position from the conveying position andlower the movable conveyor device back to the conveying position.

Various example embodiments described herein relate to the lift gateapparatus, wherein the lifting mechanism comprises a handle and a pairof gas springs.

Various example embodiments described herein relate to the lift gateapparatus, wherein the fixed conveyor device and the movable conveyordevice comprises at least one of conveyor rollers or a conveyor belt ora slider pan.

Various example embodiments described herein relate to the lift gateapparatus including the bracket which rotates about a pivot point topivot the bracket and extend it towards and over the fixed conveyordevice when the movable conveyor device is transitioned from theconveying position to the non-conveying position.

Various example embodiments described herein relate to the lift gateapparatus including the bracket which rotates about the pivot point topivot the bracket and retract it away from the fixed conveyor devicewhen the movable conveyor device is transitioned from the non-conveyingposition to the conveying position.

Various example embodiments described herein relate to the lift gateapparatus with the movable conveyor device being lifted at an angle ofat least 90 degrees relative the fixed conveyor device.

Various example embodiments described herein relate to the lift gateapparatus including the bracket which comprises a roller and an angledfront portion to slide the bracket over the fixed conveyor device suchthat the roller moves back and forth over the fixed conveyor device whenthe movable conveyor device is transitioned between the conveyingposition and the non-conveying position.

Various example embodiments described herein relate to the lift gateapparatus, wherein the angled front portion of the bracket abuts thefixed conveyor device when the movable conveyor device is at theconveying position and wherein the angled front portion of the bracketis above the fixed conveyor device when the movable conveyor device isat the non-conveying position.

Various example embodiments described herein relate to the lift gateapparatus including a locking mechanism to lock the movable conveyordevice at one of the conveying position or the non-conveying position.

Various example embodiments described herein relate to the lift gateapparatus, wherein the locking mechanism is a retractable spring pin.

Various example embodiments described herein relate to the lift gateapparatus including a sensor to determine if the movable conveyor deviceis in the conveying position or the non-conveying position.

Various example embodiments described herein relate to a conveyor systemwith plurality of conveyor devices and a lift gate apparatus. The liftgate apparatus includes a first conveyor device configured to be raisedfrom a first position to a second position and lowered back from thesecond position to the first position. A bracket attached to the firstconveyor device, wherein the bracket is configured to pivot and slideover a second conveyor device of the plurality of conveyor devices whenthe first conveyor device is raised from the first position to thesecond position.

Various example embodiments described herein relate to a conveyorsystem, wherein the lift gate apparatus further includes a liftingmechanism to raise and lower the first conveyor device from the firstposition and the second position respectively.

Various example embodiments described herein relate to a conveyorsystem, wherein the lift gate apparatus further includes a roller and anangled front portion to slide the bracket over the second conveyordevice such that the roller moves back and forth over the secondconveyor device when the first conveyor device is transitioned betweenthe first position and the second position.

Various example embodiments described herein relate to a conveyorsystem, wherein the angled front portion of the bracket abuts the secondconveyor device when the first conveyor device is at the first positionand wherein the angled front portion of the bracket is above the secondconveyor device when the first conveyor device is at the secondposition.

Various example embodiments described herein relate to a conveyorsystem, wherein the bracket is configured to bridge a gap between thefirst conveyor device and the second conveyor device when the firstconveyor device is in the first position.

Various example embodiments described herein relate to a conveyorsystem, wherein the first conveyor device is lifted to at an angle of atleast 90 degrees from the first position.

Various example embodiments described herein relate to a method foroperating a lift gate apparatus. The method including lifting a movableconveyor device to transition between a conveying position and anon-conveying position relative to a fixed conveyor device and sliding abracket over the fixed conveyor device when the movable conveyor deviceis transitioned from the conveying position to the non-conveyingposition. The method further including retracting the bracket from thefixed conveyor device when the movable conveyor device is transitionedfrom the non-conveying position to the conveying position such that thebracket bridges a gap between the movable conveyor device and the fixedconveyor device.

Various example embodiments described herein relate to the methodfurther including locking the movable conveyor device at one of theconveying position or the non-conveying position.

The above summary is provided merely for purposes of summarizing someexample embodiments to provide a basic understanding of some aspects ofthe disclosure. Accordingly, it will be appreciated that theabove-described embodiments are merely examples and should not beconstrued to narrow the scope or spirit of the disclosure in any way. Itwill be appreciated that the scope of the disclosure encompasses manypotential embodiments in addition to those here summarized, some ofwhich will be further described below.

BRIEF DESCRIPTION OF THE DRAWINGS

The description of the illustrative embodiments can be read inconjunction with the accompanying figures. It will be appreciated thatfor simplicity and clarity of illustration, elements illustrated in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements are exaggerated relative to otherelements. Embodiments incorporating teachings of the present disclosureare shown and described with respect to the figures presented herein, inwhich:

FIG. 1 illustrates a perspective view of a section of a conveyor systemhaving a lift gate apparatus in a conveying position in accordance withan embodiment of the present invention.

FIG. 2 illustrates a perspective view of a section of a conveyor systemhaving the lift gate apparatus in a non-conveying position in accordancewith an embodiment of the present invention.

FIG. 3 illustrates a perspective view of a section of a conveyor systemwithout the lift gate apparatus in accordance with an embodiment of thepresent invention.

FIG. 4 illustrates an exploded perspective view of the lift gateapparatus in accordance with an embodiment of the present invention.

FIG. 5 illustrates an exploded perspective view of a movable conveyordevice in accordance with an embodiment of the present invention.

FIG. 6 illustrates an exploded perspective view of a bracket attached tothe movable conveyor device in accordance with an embodiment of thepresent invention.

FIG. 7 illustrates a side view of the lift gate apparatus in a conveyingposition in accordance with an embodiment of the present invention.

FIG. 8 illustrates a side view of the lift gate apparatus in anon-conveying position in accordance with an embodiment of the presentinvention.

FIG. 9 illustrates a flowchart depicting a method for operating the liftgate apparatus of FIG. 1 in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION

Some embodiments of the present invention will now be described morefully hereinafter with reference to the accompanying drawings, in whichsome, but not all embodiments of the inventions are shown. Indeed, thedisclosure may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. The terms “or” and “optionally” are used herein inboth the alternative and conjunctive sense, unless otherwise indicated.The terms “illustrative” and “exemplary” are used to be examples with noindication of quality level. Like numbers refer to like elementsthroughout.

The components illustrated in the figures represent components that mayor may not be present in various embodiments of the invention describedherein such that embodiments may include fewer or more components thanthose shown in the figures while not departing from the scope of theinvention.

Turning now to the drawings, the detailed description set forth below inconnection with the appended drawings is intended as a description ofvarious configurations and is not intended to represent the onlyconfigurations in which the concepts described herein may be practiced.The detailed description includes specific details for the purpose ofproviding a thorough understanding of various concepts with likenumerals denote like components throughout the several views. However,it will be apparent to those skilled in the art that these concepts maybe practiced without these specific details.

As used herein, the terms “open position,” “non-conveying position”,“folded position” and similar terms may be used interchangeably to referto a position of the movable conveyor device in which items cannot betransported by the movable conveyor device. Thus, use of any such termsshould not be taken to limit the spirit and scope of embodiments of thepresent disclosure.

As used herein, the terms “close position,” “conveying position”,“unfolded position” and similar terms may be used interchangeably torefer to a position of the movable conveyor device in which the itemscan be transported by the movable conveyor device. Thus, use of any suchterms should not be taken to limit the spirit and scope of embodimentsof the present disclosure.

As used herein, the term “movable conveyor device” may be used to referto a conveyor zone or a conveyor unit which can be rotated about a pivotpoint. The term “fixed conveyor device” may be used to refer to aconveyor zone or a conveyor unit positioned either upstream ordownstream to the movable conveyor device. Thus, use of any such termsshould not be taken to limit the spirit and scope of embodiments of thepresent disclosure.

As used herein, the term “space”, “pathway” or “opening” may be used torefer to an area between conveyor zones of a conveyor system throughwhich an operator or a material handling vehicle can travel acrossfreely. Such an area is created by repositioning a conveyor zone. Thus,use of any such terms should not be taken to limit the spirit and scopeof embodiments of the present disclosure.

As used herein, the term “gap” may be used to refer to a space createdbetween the movable conveyor device and the fixed conveyor device afterinstallation of the conveyor system. Thus, use of any such terms shouldnot be taken to limit the spirit and scope of embodiments of the presentdisclosure.

Generally, conveyor systems may be distributed at different locationswithin a warehouse or distribution center. Few of these conveyor systemsmay be arranged close to each other in a confined space in the warehouseblocking a pathway to access other conveyor systems. Accordingly, anoperator or a material handling vehicle may be forced to maneuverthrough a complex route to reach the conveyor systems due to theblocking of the pathway. In such scenarios, time taken for the operatoror the material handling vehicle for performing activities such as orderfulfilment, picking, packing, or maintenance may increase resulting in areduced throughput. In some examples, several zones of the conveyorsystem may be arranged compactly in the confined space due to spaceconstraints. For example, the zones may be arranged in the form of arectangular shape with any one side or two sides of the rectangleabutting against a wall of the warehouse. In such scenarios,accessibility to the zones on the sides abutting the wall becomespractically impossible as there is no pathway to reach such zones. Inthis regard, the operator or the material handling vehicle may havereduced accessibility to such zones. Accordingly, the operator may beforced to dismantle a portion of the conveyor system to create a spaceor the pathway to access the other zones abutting the wall. Suchdismantling may be a laborious and a time-consuming task. Further, theoperator may be forced to cross or leap over the portion of the conveyorsystem to access other zones, however, such cross over is not feasiblewhen that conveyor system is operational. Therefore, there is a need forthe operator or the material handling vehicle to access all the conveyorzones or conveyor systems in the warehouse at ease without time delayand with minimal effort.

Further, a person skilled in the conveyor art, may use a conventionallift gate as a part of the conveyor system, which can be movable orpivotable to an open position or a non-conveying position to create thespace or the pathway for the operator or the material handling vehicleto reach an intended conveyor zone of the conveyor system. Suchconventional lift gates have several drawbacks, such as, but not limitedto use of multiple mounting components beneath the lift gate forsupport, use of multiple mounting brackets upstream and downstream ofthe lift gate for attachment with neighboring zones, use of conventionalmechanisms which slams the lift gate against the conveyor frame whenpivoting the lift gate between the open position and a close position.

In an example, when using multiple mounting components, for example,mounting brackets or mounting struts, beneath the conveyor lift gate forsupport, the multiple mounting components may hinder a movement of theoperator and the material handling vehicle when the lift gate is in theopen position or non-conveying position. For example, a portion of thesemultiple mounting components may protrude out when the lift gate is inthe open position or non-conveying position and such portions maypartially block the pathway and may raise safety concerns for theoperator and the material handling vehicle when travelling past the liftgate as there is a risk of collision and unexpected slamming of the liftgate from the open position to the close position as result of thecollision.

In another example, when using multiple mounting brackets upstream anddownstream of the conveyor lift gate for attachment to the upstreamconveyor and the downstream conveyor, a gap is created between theupstream/downstream conveyor and the lift gate. This gap may increasethe risk of small items being conveyed on the conveyor system to betrapped in the gap leading to an operational failure of the conveyorsystem. Further, installation of multiple mounting brackets may belaborious and may involve modifying or adding additional components toboth upstream conveyor and the downstream conveyor which makes the liftgate to be used only for a specific conveyor system and cannot beretrofitted into any other existing conveying system.

In yet another example, when using mechanisms which slams the lift gateagainst the conveyor frame when pivoting the lift gate, there is apossibility of a physical damage of the lift gate and the conveyor framewhich may lead to increase in maintenance and repair costs. Further,there is a possibility of the operator's finger to be pinched betweenthe lift gate and the conveyor frame when the lift gate slams againstthe conveyor frame.

Through applied effort, ingenuity, and innovation, many of the aboveidentified problems have been solved by developing solutions that areincluded in embodiments of the present disclosure, many examples ofwhich are described in detail herein. The present disclosure relates toa lift gate apparatus with a movable conveyor device configured totransition between a conveying position and a non-conveying position. Abracket attached to the movable conveyor device configured to bridge agap between the movable conveyor device and a fixed conveyor device,wherein the bracket pivots and slides over the fixed conveyor devicewhen the movable conveyor device is transitioned from the conveyingposition to the non-conveying position.

According to an embodiment, the bracket rotates about a pivot point topivot the bracket and extend it towards and over the fixed conveyordevice when the movable conveyor device is transitioned from theconveying position to the non-conveying position.

According to an embodiment, the bracket rotates about the pivot point topivot the bracket and retract it away from the fixed conveyor devicewhen the movable conveyor device is transitioned from the non-conveyingposition to the conveying position.

According to an embodiment, the bracket comprises a roller and an angledfront portion to slide the bracket over the fixed conveyor device suchthat the roller moves back and forth over the fixed conveyor device whenthe movable conveyor device is transitioned between the conveyingposition and the non-conveying position.

According to an embodiment, the lift gate apparatus further comprises alifting mechanism to lift the movable conveyor device to thenon-conveying position from the conveying position and lower the movableconveyor device back to the conveying position. The lifting mechanismcomprises a handle and a pair of gas springs.

In the following detailed description of exemplary embodiments of thedisclosure, specific representative embodiments in which the disclosuremay be practiced are described in sufficient detail to enable thoseskilled in the art to practice the disclosed embodiments. For example,specific details such as specific method orders, structures, elements,and connections have been presented herein. However, it is to beunderstood that the specific details presented need not be utilized topractice embodiments of the present disclosure. It is also to beunderstood that other embodiments may be utilized and that logical,architectural, programmatic, mechanical, electrical and other changesmay be made without departing from the general scope of the disclosure.The following detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present disclosure is defined bythe appended claims and equivalents thereof.

Throughout this specification, the term ‘conveyors’ or ‘conveyordevices’ may be used interchangeably and these terms should be taken asan example of both roller conveyor, a belt conveyor or theircombination.

Throughout this specification, the term ‘rollers’ or ‘conveyor rollers’may be used interchangeably and the term ‘belt’ or ‘conveyor belt’ maybe used interchangeably and should be taken as an example of a mediumwhich transports items on the conveyor system.

Referring now specifically to the drawings and the illustrativeembodiments depicted therein, FIG. 1 illustrates a perspective view of asection of a conveyor system having a lift gate apparatus 100 in aconveying position in accordance with an embodiment of the presentinvention. The section of the conveyor system as shown in FIG. 1includes a conveyor frame 102 supporting multiple conveyor devices. Oneof the multiple conveyor devices acts a lift gate apparatus 100. Asshown in FIG. 1 , the lift gate apparatus 100 is positioned in betweentwo conveyor devices 104 a, 104 b. The two conveyor devices 104 a, 104 bmay be fixed conveyor devices with one fixed conveyor device 104 apositioned upstream of the lift gate apparatus 100 and another fixedconveyor device 104 b positioned downstream of the lift gate apparatus100. According to an embodiment, the lift gate apparatus 100 comprises amovable conveyor device 106. The movable conveyor device 106 beingpositioned in between the upstream and downstream fixed conveyor devices104 a, 104 b. A portion of the conveyor frame 102 is removed from FIG. 1for clarity such that the lift gate apparatus 100 and associatedcomponents are clearly visible. An item is transported from the upstreamfixed conveyor device 104 a to the downstream fixed conveyor device 104b in a direction of travel indicated by arrows shown in FIG. 1 . Forexplanation of the illustration shown in FIG. 1 , the movable conveyordevice may 106 be considered as a first conveyor device and thedownstream fixed conveyor device 104 b may be considered a secondconveyor device and the item travelling downstream from the firstconveyor device 106 to the second conveyor device 104 b and so on. Insome examples, the first conveyor device 106 and the second conveyordevice 104 b comprises at least one of conveyor rollers or a conveyorbelt or a slider pan. In the illustration shown in FIG. 1 , the firstconveyor device 106 and the second conveyor device 104 b comprisesconveyor rollers 107. In the embodiment shown in FIG. 1 , the conveyorrollers 107 of the second conveyor device 104 b are positionedperpendicular to the conveyor rollers 107 of the first conveyor device106, however, feasible are other arrangements in which the conveyorrollers 107 of the second conveyor device 104 b and the first conveyordevice 106 are positioned in parallel. As shown in FIG. 1 , the firstconveyor device 106 includes a pair of side frames 108 and the conveyorrollers 107 positioned in between the pair of side frames 108. Theconveyor rollers 107 may include idler rollers and a motor driven roller(MDR). The motor-driven roller may drive the idler rollers throughO-bands or O-rings. One of the pair of side frames 108 is a locking sideframe and the other side frame is a non-locking side frame. According toan embodiment, the locking side frame includes components configured tolock the movable conveyor device 106 in the conveying position as shownin FIG. 1 and a non-conveying position as shown in FIG. 2 . Further,each of the side frames 108 include a top portion 109 and a side portion110 to receive components configured to support and lift the movableconveyor device 106. These components are explained in detail in theexploded view shown in FIGS. 4, 5 and 6 .

According to an embodiment, the movable conveyor device 106 is rotatedor pivoted from the conveying position to the non-conveying position andvice-versa. The movable conveyor device 106 creates a space or a pathway201 as shown in FIG. 2 for an operator or a material handling vehicle topass through the pathway 201 when the movable conveyor device 106 istransitioned from the conveying position to the non-conveying position.In some examples, the material handling vehicle may a forklift, an AGV(Automated Guided Vehicle), a AMR (Autonomous mobile vehicle), a trolleycart and other vehicles transporting items within the warehouse. Forexample, in the non-conveying position, as shown in FIG. 2 , the movableconveyor device 106 does not transport any item and allows the operatoror the material handling vehicle to travel across the movable conveyordevice 106 via the pathway 201. According to an embodiment, when themovable conveyor device 106 is in the non-conveying position, anoperation of the section of the conveyor system is temporarily halted.For example, in the conveying position, as shown in FIG. 1 , the movableconveyor device 106 acts as an intermediate conveyor between theupstream fixed conveyor device 104 a and the downstream fixed conveyordevice 104 b transporting an item from the upstream fixed conveyordevice 104 a to the downstream fixed conveyor device 104 b.

According to an embodiment, the movable conveyor device 106 is pivotedto the non-conveying position from the conveying position to create thespace or the pathway 201. In some examples, the movable conveyor device106 is pivoted and positioned at a 90-degree angle with respect to thedownstream fixed conveyor device 104 b in the non-conveying position.Further, as shown in FIG. 2 , the movable conveyor device 106 does notobstruct the created space or the pathway 201 when the movable conveyordevice 106 is in the non-conveying position. For example, a first lengthX1 of the space or the pathway 201, as shown in FIG. 3 , between the twofixed conveyor devices 104 a, 104 b without installing the movableconveyor device 106 is equal to a second length X2 of the space or thepathway 201, as shown in FIG. 2 , between the two fixed conveyor devices104 a, 104 b with the movable conveyor device 106. Accordingly, it isunderstood that there is no difference in the first length X1 and thesecond length X2 of the space or pathway 201 existing before and createdafter installation of the lift gate apparatus 100. In other words, thespace or the pathway 201 created by the lift gate apparatus 100 isunobstructed by any components of the lift gate apparatus 100. In someexamples, the pathway 201 created by the movable conveyor device 106allows the operator or the material handling vehicle to easily accessany zone of the conveyor system located within the confined space in thewarehouse without any collision against the components of the lift gateapparatus 100 as there is no difference in the length X1, X2 of thespace or pathway 201 before and after installation of the lift gateapparatus 100. As shown in FIG. 2 , the lift gate apparatus 100 does notinclude any components positioned underneath the lift gate apparatus 100that protrude or obstruct the pathway 100. In this regard, a time takenfor the operator or the material handling vehicle to cross the pathwayis greatly reduced without compromising the safety of the operator andthe material handling vehicle. The lift gate apparatus 100 shown in FIG.1 may be simple in construction with fewer components than conventionallift gates known in the conveyor art. According to an embodiment, thelift gate apparatus 100 further comprises a bracket 112, a liftingmechanism 114 a, 114 b, 116 and a locking mechanism 118. The componentsof the bracket 112, lifting mechanism 114 a, 114 b, 116 and the lockingmechanism 118 is explained in detail in conjunction with FIGS. 4, 5 and6 .

FIG. 4 illustrates an exploded perspective view of the lift gateapparatus in accordance with an embodiment of the present invention. Asdiscussed previously, the lift gate apparatus 100 comprises the movableconveyor device 106, the bracket 112, the lifting mechanism 114 a, 114b, 116 and the locking mechanism 118. In FIG. 4 , the movable conveyordevice 106 is shown to be detached from the downstream fixed conveyordevice 104 b such that mounting components to mount the movable conveyordevice 106 with the downstream fixed conveyor device 104 b are clearlyvisible. According to an embodiment, the movable conveyor device 106 isattached to the downstream fixed conveyor device 104 b with the mountingcomponents such as a mount plate 402, a hinge mount block 404 and ahinge plate 406. The mounting components are coupled to each other usingsuitable fasteners 401, such as, but not limited to a nut, a bolt, awasher, a screw, a clip, a clamp and their combination. For example, thehinge mount block 404 is fastened to the conveyor frame 102 of thedownstream fixed conveyor device 104 b using the suitable fasteners 401.In some examples, the hinge mount block 404 may be an integral componentof the conveyor frame 102. According to an embodiment, the hinge mountblock 404 and the hinge plate 406 are coupled to each other using thesuitable fasteners 401. In some examples, the hinge mount block 404includes first apertures 404 a to receive the suitable fasteners 401.

According to an embodiment, the hinge plate 406 includes a first segment406 a, a second segment 406 b and a hinge 406 c between the firstsegment 406 a and the second segment 406 b. The first segment 406 a, thesecond segment 406 b and the hinge 406 c exists as a single moldedpiece. The first segment 406 a includes first holes 407 a and the secondsegment 406 b includes second holes 407 b. According to an embodiment,the first holes 407 a of the hinge plate 406 are seated on top of thefirst apertures 404 a of the hinge mount block 404 and secured togetherusing the suitable fasteners 401. For example, the first apertures 404 aand the first holes 407 a may be equidistantly distributed with thefirst holes 407 a overlapping the first apertures 404 a when the hingeplate 406 is seated on the hinge mount block 404. In some examples,number of first holes 407 a on the first segment 406 a may be equal tonumber of first apertures 404 a on the hinge mount block 404. Accordingto an embodiment, the first apertures 404 a may be provided on theconveyor frame 102 without use of the hinge mount block 404. In suchscenarios, the hinge plate 406 may be attached directly to the firstapertures 404 a of conveyor frame 102. In some examples, the first holes407 a and the first apertures 404 a may be threaded or non-threadeddepending on a type of fastener employed to couple the hinge plate 406and the hinge mount block 404.

According to an embodiment, the second segment 406 b of the hinge plate406 is attached to the mount plate 402. The mount plate 402 includessecond apertures 402 a. According to an embodiment, the second apertures402 a of the mount plate 402 are seated on top of the second holes 407 bof the hinge plate 406 and secured together using the suitable fasteners401. For example, the second apertures 402 a and the second holes 407 bmay be equidistantly distributed with the second holes 407 b overlappingthe second apertures 402 a when the mount plate 402 is seated on thehinge plate 406. In some examples, the number of second holes 407 b onthe second segment 406 b may be equal to the number of second apertures402 a on the mount plate 402. According to an embodiment, the secondapertures 402 a may be provided on a bottom portion (not shown) of thepair of side frames 108 of the movable conveyor device 106 without useof the mount plate 402. In such scenarios, the second segment 406 b maybe attached directly to the bottom portion of the pair of side frames108. In some examples, the second holes 407 b and the second apertures402 a may be threaded or non-threaded depending on the type of fasteneremployed to couple the hinge plate 406 and the mount plate 402.According to an embodiment, the mount plate 402 may be coupled to thebottom portion of the pair of side frames 108 using third apertures 402b. In this regard, the second apertures 402 a are used for coupling withthe hinge plate 406 and the third apertures 402 b are used for couplingwith the bottom portion of the pair of side frames 108.

In this regard, the first segment 406 a of the hinge plate 406 isattached to the hinge mount block 404 and the second segment 406 b ofthe hinge plate 406 is attached to the mount plate 402. Therefore, thehinge plate 406 appears to be a component connecting the mount plate 402with the hinge mount block 404. Accordingly, the movable conveyor device106 is coupled to the downstream fixed conveyor device 104 b using thehinge plate 406 and the mount plate 402. According to an embodiment, thehinge 406 c of the hinge plate 406 acts as a pivot point for pivotingthe movable conveyor device 106 from the conveying position to thenon-conveying position. According, to an embodiment, the hinge mountblock 404 may be provided with a wear-resisting pad (not shown) to avoidwear and tear of the hinge mount block 404 as there is a possibility ofthe hinge mount block 404 to corrode and rust over time due to repeatedpivoting of the movable conveyor device 106.

According to an embodiment, the lifting mechanism comprises a handle 116and a pair of gas springs 114 a, 114 b. The handle 116 and the pair ofgas springs 114 a, 114 b is attached to the movable conveyor device 106.For example, the pair of gas springs 114 a, 114 b includes a first gasspring 114 a and a second gas spring 114 b, each having a pair ofmounting portions 414 a, 414 b, 416 a, 416 b. For example, the first gasspring 114 a includes a first pair of mounting portions 414 a, 414 b,each positioned in opposing ends of the first gas spring 114 a.Similarly, the second gas spring 114 b includes a second pair ofmounting portions 416 a, 416 b, each positioned in opposing ends of thesecond gas spring 114 b. One of the mounting portion 414 a of the firstpair of mounting portions 414 a, 414 b is coupled to the movableconveyor device 106 and the other mounting portion 414 b is coupled tothe conveyor frame 102. Similarly, one of the mounting portion 416 a ofthe second pair of mounting portions 416 a, 416 b is coupled to themovable conveyor device 106 and the other mounting portion 41 bb iscoupled to the conveyor frame 102. As shown in FIG. 1 and FIG. 3 , themounting portions 414 b, 416 b are coupled to a vertical mast 103 of theconveyor frame 102 and the other mounting portions 414 a, 416 a arecoupled to the side portion 110 of the locking side of the side frame108. According to an embodiment, the first pair mounting portions 414 a,414 b and the second pair of mounting portions 416 a, 416 b on the firstgas spring 114 a and the second gas spring 114 b are shoulder bolts.According to another embodiment, the first pair mounting portions 414 a,414 b and the second pair of mounting portions 416 a, 416 b may be anysuitable fastener known to a person skilled in the art to couple thefirst gas spring 114 a and the second gas spring 114 b with the movableconveyor device 106 and the conveyor frame 102. According to anembodiment, the first gas spring 114 a and the second gas spring 114 bmay include a pressurized gas cylinder 120 and a piston rod 121 ascommonly known in the art configured to raise and lower heavy masseswithout much effort. The piston rod 121 may slide into the interior ofthe pressurized gas cylinder 120 compressing volume and increasingpressure inside the cylinder 120 when the movable conveyor device 106 istransitioned from the conveying position to the non-conveying position.

According to an embodiment, as shown in FIG. 5 , the handle 116 isattached to the bottom portion (not shown) of the locking side of theside frame 108 using the suitable fasteners 501 known in the art, suchas, but not limited to, a nut, a bolt, a washer, a screw, a clip, aclamp and their combination. In some examples, the handle 116 may beattached on the top portion 109 or the side portion 110 of the lockingside of the side frame 108 using the suitable fasteners 501. Accordingto an embodiment, as shown in FIG. 5 , the movable conveyor device 106includes a first gas spring pivot block 504 a positioned on the sideportion 110 of each of the side frames 108. The first gas spring pivotblock 504 a is coupled to the side portion 110 using the suitablefasteners 501. The first gas spring pivot block 504 a receives one ofthe mounting portions 414 a, for example, the shoulder bolt of the firstgas spring 114 a. For example, the first gas spring pivot block 504 aincludes a first opening 504 c which mates with the shoulder bolt 414 aof the first gas spring 504 a to establish a pivoting connection betweenthe first gas spring 114 a and the first gas spring pivot block 504 a.Likewise, the second gas spring 114 b is mounted to the side portion 110of the side frame 108 using a second gas spring pivot block 504 b. Forexample, the second gas spring pivot block 504 b includes a secondopening (not shown) which mates with the shoulder bolt 416 a of thesecond gas spring 114 b to establish a pivoting connection between thesecond gas spring 114 b and the second gas spring pivot block 504 b. Inthis regard, the first gas spring 114 a and the second gas spring 114 bare coupled to the movable conveyor device 106. Further, other mountingportions 414 b, 416 b as shown in FIG. 4 is mounted to a correspondingspring mounting block (not shown) coupled to the vertical mast 103 (asshown in FIGS. 1 and 2 ) of the conveyor frame 102. The first gas spring114 a and the second gas spring 114 b may be configured to handle aweight of the movable conveyor device 106 at the conveying position andconfigured to gradually move the movable conveyor device 106 from theconveying position to the non-conveying position and vice-versa when themovable conveyor device 106 is lifted using the handle 116.

According to an embodiment, the locking mechanism 118 includes a lockingpin 508 and a locking pin mount block 510. The locking pin mount block510 is coupled to the side portion 110 of the locking side of the sideframe 108 using the suitable fasteners 501. According to an embodiment,the locking pin mount block 510 includes a provision to mount thelocking pin 508. The locking pin 508 is mounted on the locking pin mountblock 510 using the suitable fasteners 501. In some example, the lockingpin 508 can be a pin with a retractable spring mechanism to lock themovable conveyor device 106 at the conveying position and thenon-conveying position. In some examples, the locking pin 508 can be apin with a latching mechanism to lock the movable conveyor device 106 atthe conveying position and the non-conveying position. According to anembodiment, the vertical conveyor frame 102 may include a lockingbracket 119 (as shown in FIG. 2 ) to receive the locking pin 508. Insome examples, the locking bracket 119 may be positioned above thesecond gas spring pivot block 504 b. The locking pin 508 is insertedinto the locking bracket 119 to lock the movable conveyor device 106with the conveyor frame 102 in the non-conveying position. In thisregard, the locking mechanism 118 may prevent an accidental fall of thelift gate apparatus 100 when placed in the non-conveying position.According to an embodiment, the movable conveyor device 106 furtherincludes a photo eye sensor 511 mounted on a sensor mount 512 positionedon the top portion 109 of the locking side of the side frame 108 todetect presence of items transported on the movable conveyor device 106.According to an embodiment, the movable conveyor device 106 furtherincludes additional sensors (not shown), such as, but not limited to aproximity switch with corresponding sensor mount to detect whether themovable conveyor device 106 is in the conveying position or thenon-conveying position.

According to an embodiment, as shown in FIG. 6 , the bracket 112 isattached to the movable conveyor device 106. The bracket 112 bridges agap 201 between the movable conveyor device 106 and the downstream fixedconveyor device 104 b as shown in FIG. 1 such that the items transporteddownstream the movable conveyor device 106 are not stuck or trapped inthe gap 201 leading to damage of the items. As shown in FIG. 6 , thebracket 112 is attached to the side portion 110 of each side frame 108of the movable conveyor device 106. According to an embodiment, as shownin FIG. 6 , the bracket 112 includes multiple rollers 602 positioned inbetween a pair of support frames 604 a, 604 b. According to anotherembodiment, the bracket 112 includes at least one roller positioned inbetween the pair of support frames 604 a, 604 b. Further, each supportframe 604 a, 604 b includes roller openings 606 to receive axles 603 ofthe rollers 606. As shown in FIG. 6 , the bracket 112 further includes asupport plate 608 with the rollers 602 resting on top of the supportplate 608. The support plate 608 acts as a bridge connecting the pair ofsupport frames 604 a, 604 b as shown in FIGS. 5 and 6 . According toanother embodiment, the rollers 602 may be positioned between the pairof support frames 604 a, 604 b without the requirement of the supportplate 608. According to an embodiment, each of the support frames 604 a,604 b include a first end 610 a, 612 a and a second end 610 b, 612 b.The second end 610 b, 612 b is pivotably coupled to the side portion 110of each side frame 108 of the movable conveyor device 106 using suitablefasteners 601, such as, but not limited to, a pivot bearing, a bearingspacer, a bolt sleeve, a nut, a washer, or their combination. In thisregard, a pivot point is formed for the bracket 112 to be rotated bypivotably coupling the second end 610 b, 612 b with the side frame 108using the suitable fasteners 601. According to an embodiment, thebracket 112 rotates about the pivot point to pivot the bracket 112 andextend it towards and over the downstream fixed conveyor device 104 awhen the movable conveyor device 106 is transitioned from the conveyingposition to the non-conveying position.

As shown in FIG. 6 , the bracket 112 further includes a gliding plate620 coupled to the support plate 608. The gliding plate 620 abuts thefirst end 610 a, 612 a of the pair of support frames 604 a, 604 b whenthe gliding plate 620 is coupled to the support plate 608. According toan embodiment, the gliding plate 620 may be attached directly to thepair of support frames 604 a, 604 b without the requirement of thesupport plate 608. According to an embodiment, the gliding plate 620 isan angular plate with two opposing surfaces 620 a, 620 b bifurcated atan obtuse angle. The gliding plate 620, the support plate 608 and thefirst end 610 a, 612 a of the pair of support frames 604 a, 604 b whencoupled together forms an angled front portion for the bracket 112. Theangled front portion is configured to slide the bracket 112 over thedownstream fixed conveyor device 104 b such that the rollers 602 on thebracket 112 can move back and forth over the downstream fixed conveyordevice 104 b when the movable conveyor device 106 is transitionedbetween the conveying position and the non-conveying position andvice-versa. According to an embodiment, as shown in FIG. 7 , the angledfront portion of the bracket 112 abuts the downstream fixed conveyordevice 104 b when the movable conveyor device 106 is at the conveyingposition, According to an embodiment, as shown in FIG. 8 , the angledfront portion is above the downstream fixed conveyor device 104 b whenthe movable conveyor device 106 is at the non-conveying position.

In the embodiment shown in FIG. 7 , the gap existing between thedownstream fixed conveyor device 104 b and the movable conveyor device106 in the conveying position is bridged using the bracket 112 withmultiple rollers 602 as previously discussed. The bracket 112 with themultiple rollers 602 allows a smooth transition of the item conveyedfrom the movable conveyor device 106 to the downstream fixed conveyordevice 104 b. As shown in FIG. 7 , the piston rod 121 of the gas springs114 a is in the expanded position fully extended from the pressurizedgas cylinder 120 providing a support to the movable conveyor device 106at the conveying position. The piston rod 121 of the gas spring 114 a iscompressed into the pressurized gas cylinder 120 when the movableconveyor device 106 is lifted from the conveying position. As shown inFIG. 8 , the piston rod 121 of the gas spring 114 a is in the fullycompressed position when the movable conveyor device 106 is in thenon-conveying position. In this regard, the movable conveyor device 106may be transitioned gradually from the conveying position to thenon-conveying position and vice-versa by expansion and compression ofthe gas spring 114 a. According to an embodiment, the movable conveyordevice 106 is lifted from the conveying position to the non-conveyingposition using the handle 116 attached to the movable conveyor device106. As shown in FIG. 8 , the handle 116 is structured in a manner to bein parallel with the vertical mast 103 and fully housed within a widthof the vertical mast 103 of the conveyor frame 102 such that the handle116 does not protrude or obstruct the pathway 201 (shown in FIG. 2 )when the movable conveyor device 106 is in the non-conveying position.

According to an embodiment, when the movable conveyor device 106 istransitioned from the conveying position to the non-conveying position,the bracket 112 rotates about the pivot point on the movable conveyordevice 106 to pivot the bracket 112 and extend it towards and over thedownstream fixed conveyor device 104 b. As shown in FIG. 8 , the bracket112 with multiple rollers 602 is positioned above the downstream fixedconveyor device 104 b in the non-conveying position. Similarly, when themovable conveyor device 106 is transitioned from the non-conveyingposition to the conveying position, the bracket 112 rotates about thepivot point to pivot the bracket 112 and retract it away from thedownstream fixed conveyor device 104 b. As shown in FIG. 7 , the bracket112 with multiple rollers 602 is in the retracted state abutting thedownstream fixed conveyor device 104 b and bridging the gap between thedownstream fixed conveyor device 104 b and the movable conveyor device106. Further, as shown in FIG. 8 , the movable conveyor device 106 islocked in the non-conveying position using the locking mechanism 118.The locking pin 508 is inserted into the locking bracket 119 on theconveyor frame 102 to lock the movable conveyor device 106 in thenon-conveying position. As shown in FIG. 8 , the movable conveyor device106 is structured in a manner to be in parallel with the vertical mast103 and fully housed within the width of the vertical mast 103 of theconveyor frame 102 such that the movable conveyor device 106 does notprotrude or obstruct the pathway 201 (shown in FIG. 2 ) when the movableconveyor device 106 is in the non-conveying position. According to anembodiment, when the movable conveyor device is in the non-conveyingposition, the movable conveyor device 106 may be positioned at an angleof about 90-degree with respect to the downstream fixed conveyor device.As shown in FIG. 8 , when the movable conveyor device 106 is positionedat the 90-degree angle, the bracket 112 with multiple rollers 602 isfully positioned on top of the conveyor rollers 107 of the downstreamfixed conveyor device 104 b.

Unlike conventional lift gate, the lift gate apparatus of the presentdisclosure minimizes use of multiple mounting components beneath thelift gate and bridges a gap between the lift gate and neighboringdownstream conveyor devices. As shown in FIGS. 7 and 8 , the lift gateapparatus bridges the gap between the lift gate apparatus and theneighboring conveyor devices while maintaining minimal lifting andmounting components (as shown in FIG. 4 ). In this regard, the lift gateapparatus of the present disclosure does not obstruct the pathway of theoperator and the material handling vehicle. Further, the lift gateapparatus uses the gas springs and the locking pin to address the safetyissues due to slamming effect of conventional lift gates. Further, thelift gate appratus can be retrofitted to any conveyor systems as itrequires minimal lifting and mounting components. Therefore, the liftgate apparatus of the present disclosure provides an unobstructed safepathway for the item and the operator and the material handling vehicleby the synergetic operation of components such as the movable conveyordevice, the lifting mechanism, the locking mechanism and the bracket.

FIG. 9 illustrates a flowchart depicting a method for operating the liftgate apparatus of FIG. 1 in accordance with an embodiment of the presentinvention. The lift gate apparatus includes a movable conveyor device, alifting mechanism, a locking mechanism and a bracket. The liftingmechanism includes a handle and a pair of gas springs. At step 902, themovable conveyor device is lifted using the handle from a conveyingposition to a non-conveying position. For example, an operator may usethe handle to hold and lift the movable conveyor device from theconveying position to the non-conveying position and vice-versa. Whenthe movable conveyor device is lifted from the conveying position to thenon-conveying position and vice-versa, the gas spring is configured togradually transition the movable conveyor device by compressing andexpanding the gas spring such that a smooth transition is maintainedwithout sudden impact or jerk avoiding accidental fall back. Further,when the movable conveyor device is transitioned to the non-conveyingposition, the movable conveyor device is locked with the conveyor frameusing the locking mechanism. The locking mechanism includes a lockingpin and a locking bracket. The locking pin attached to the movableconveyor device is latched to the locking bracket on the conveyor frameto hold the movable conveyor device at the non-conveying positionpreventing from accidental fall back of the movable conveyor device tothe conveying position. When the movable conveyor device is transitionedto the non-conveying position using the lifting mechanism, a space or apathway is created for the operator or the material handling vehicle asshown in FIGS. 2 and 3 allowing the operator and the material handlingvehicle to pass through the pathway.

When the movable conveyor device is gradually lifted to thenon-conveying position using the handle and the gas spring, at step 904,the bracket attached to the movable conveyor device gradually slidesover a fixed conveyor device positioned downstream of the movableconveyor device. The bracket includes an angled front portion whichfacilitates the bracket to slide over the fixed conveyor device. Thebracket includes rollers positioned adjacent to the angled front portionsuch that the bracket may move back and forth over the fixed conveyordevice. According to an embodiment, the bracket rotates about a pivotpoint on the movable conveyor device to pivot the bracket and extend ittowards and over the fixed conveyor device when the movable conveyordevice is transitioned from the conveying position to the non-conveyingposition.

According to an embodiment, the movable conveyor device is transitionedback to the conveying position by releasing the locking pin and loweringthe movable conveyor device under the influence of the gas spring. Whilethe movable conveyor device is transitioned to the conveying position,at step 906, the bracket simultaneously retracts from the fixed conveyordevice such that the bracket bridges a gap between the movable conveyordevice and the fixed conveyor device allowing the items to pass over thebracket without getting trapped in the gap. According to an embodiment,the bracket rotates about the pivot point to pivot the bracket andretract it away from the fixed conveyor device when the movable conveyordevice is transitioned from the non-conveying position to the conveyingposition.

Further, at step 908, after the movable conveyor device is transitionedto the conveying position the locking pin latches with another lockingbracket on the conveyor frame to hold the movable conveyor device at theconveying position and to avoid accidental lifting of the movableconveyor device during normal operation. In this regard, the movableconveyor device is locked in both the conveying position and thenon-conveying position to prevent accidental fall back and accidentallifting. Therefore, the components of the lift gate apparatus such asthe movable conveyor device, the lifting mechanism, the lockingmechanism and the bracket operates in synergy to create a pathway forthe item and the operator or the material handling vehicle withoutcompromising on the safety. Since the lift gate apparatus has fewermounting components such as the gas spring, the hinge plate and thebracket attached to the movable conveyor device, the lift gate apparatusmay be retrofitted to any conveyor system requiring a safe pathway forthe item as well the operator or the material handling vehicle.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

The foregoing description of an embodiment has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed.Obvious modifications or variations are possible in light of the aboveteachings. The embodiment was chosen and described in order to bestillustrate the principles of the invention and its practical applicationto thereby enable one of ordinary skill in the art to best utilize theinvention in various embodiments and with various modifications as aresuited to the particular use contemplated. Although only a limitednumber of embodiments of the invention are explained in detail, it is tobe understood that the invention is not limited in its scope to thedetails of construction and arrangement of components set forth in thepreceding description or illustrated in the drawings. The invention iscapable of other embodiments and of being practiced or carried out invarious ways. Also, in describing the embodiment, specific terminologywas used for the sake of clarity. It is to be understood that eachspecific term includes all technical equivalents which operate in asimilar manner to accomplish a similar purpose.

The invention claimed is:
 1. A lift gate apparatus, comprising: a firstconveyor device; and a bracket that includes at least one roller, thebracket is configured to bridge a gap between the first conveyor deviceand a second conveyor device when the first conveyor device istransitioned from a conveying position to a non-conveying position, andwherein the bracket rotates about a pivot point to pivot the bracket andextend it towards and over the second conveyor device when the firstconveyor device is transitioned from the conveying position to thenon-conveying position.
 2. The lift gate apparatus of claim 1, whereinthe bracket is further configured to couple with the first conveyordevice.
 3. The lift gate apparatus of claim 1, further comprising alifting mechanism to lift the first conveyor device to the non-conveyingposition from the conveying position and lower the first conveyor deviceback to the conveying position.
 4. The lift gate apparatus of claim 3,wherein the lifting mechanism comprises a handle and a pair of gassprings.
 5. The lift gate apparatus of claim 1, wherein each of thefirst conveyor device and the second conveyor device comprises at leastone of conveyor rollers or a conveyor belt or a slider pan.
 6. The liftgate apparatus of claim 1, wherein the bracket rotates about the pivotpoint to pivot the bracket and retract it away from the second conveyordevice when the first conveyor device is transitioned from thenon-conveying position to the conveying position.
 7. The lift gateapparatus of claim 1, wherein the first conveyor device is lifted to atan angle of at least 90 degrees relative the second conveyor device. 8.The lift gate apparatus of claim 1, wherein the bracket comprises anangled front portion to slide the bracket over the second conveyordevice such that the at least one roller moves back and forth over thesecond conveyor device when the first conveyor device is transitionedbetween the conveying position and the non-conveying position.
 9. Thelift gate apparatus of claim 8, wherein the angled front portion of thebracket abuts the second conveyor device when the first conveyor deviceis at the conveying position and wherein the angled front portion of thebracket is above the second conveyor device when the first conveyordevice is at the non-conveying position.
 10. The lift gate apparatus ofclaim 1, further comprising a locking mechanism to lock the firstconveyor device at one of the conveying position or the non-conveyingposition.
 11. The lift gate apparatus of claim 10, wherein the lockingmechanism is a retractable spring pin.
 12. The lift gate apparatus ofclaim 1, further comprising a sensor to determine if the first conveyordevice is in the conveying position or the non-conveying position.
 13. Aconveyor system comprising: a first conveyor device; a second conveyordevice; a lift gate apparatus; and a bracket that includes at least oneroller, the bracket is configured to bridge a gap between the firstconveyor device and a second conveyor device when the first conveyordevice is raised from a first position to a second position, and whereinthe lift gate apparatus further comprises an angled front portion toslide the bracket over the second conveyor device such that the at leastone roller moves back and forth over the second conveyor device when thefirst conveyor device is transitioned between the first position and thesecond position.
 14. The conveyor system of claim 13, wherein thebracket is further configured to couple with the first conveyor device.15. The conveyor system of claim 13, wherein the lift gate apparatusfurther comprises a lifting mechanism to raise and lower the firstconveyor device from the first position and the second positionrespectively.
 16. The conveyor system of claim 13, wherein the angledfront portion of the bracket abuts the second conveyor device when thefirst conveyor device is at the first position and wherein the angledfront portion of the bracket is above the second conveyor device whenthe first conveyor device is at the second position.
 17. The conveyorsystem of claim 13, wherein the bracket is configured to bridge a gapbetween the first conveyor device and the second conveyor device whenthe first conveyor device is in the first position.
 18. The conveyorsystem of claim 13, wherein the first conveyor device is lifted to at anangle of at least 90 degrees from the first position.